The failure of components on an aircraft, and in particular moving components on a helicopter such as rotor transmission gears, can result in catastrophic consequences. As such, aircraft are often kept on strict maintenance and component replacement schedules based on the hours of operation. These static, predetermined maintenance and replacement schedules are developed considering worst case component failure rates based on statistical data compilations and load cell testing. However, in some instances these replacement schedules may indicate replacement time intervals that are too aggressive, which can result in needless replacement of healthy components. Since aircraft components are often quite expensive, the cost associated with needless replacement of healthy components can be relatively high. Additionally, there is an operation cost of removing aircraft from service when in fact no maintenance is required. Further, in some instances replacement schedules may indicate a replacement time interval that is too relaxed, such as when faulty or defective materials are installed, which can result in unexpected component failure and unscheduled maintenance. Unscheduled maintenance results in lost revenue and decreased operational readiness, both which are important to aircraft operators.
As a result of these issues with the accuracy of component replacement schedules, Health and Usage Monitoring Systems (HUMS) have been developed. A HUMS can process vibration data associated with a component to generate condition indicators (CI). These condition indicators are descriptive statistics of a component. Transmission of power to rotors and other moving components of an aircraft induce vibrations in the structures supporting the moving components. The vibrations can occur at frequencies that correspond to a shaft rotation rate, mesh rate, bearing passing frequency or the like, as well as their harmonics. Changes in these frequencies can be indicative of the health of the components. As such, the vibration frequencies can be sensed by vibration sensors, and associated data can be gathered by a HUMS. The HUMS can then analyze the vibration data and determine the health of the components by evaluating the condition indicators.
Utilization of the vibration data to predict component failures is difficult. As such, improved mechanisms for analyzing vibration data to determine the health of components would be desirable. In particular, it would be desirable to develop an improved mechanism for determining a time when actions can be taken with respect to a component. As described above, such a solution can result in increased safety and cost savings.